Topics
Number System(Consolidating the Sense of Numberness)
Number System
Estimation
Ratio and Proportion
Algebra
Numbers in India and International System (With Comparison)
Geometry
Place Value
Mensuration
Natural Numbers and Whole Numbers (Including Patterns)
Data Handling
Negative Numbers and Integers
Number Line
HCF and LCM
Playing with Numbers
- Simplification of Brackets
- Finding Factors Using Rectangular Arrangements and Division
- Factors and Common Factors
- Multiples and Common Multiples
- Concept of Even and Odd Number
- Tests for Divisibility of Numbers
- Divisibility by 2
- Divisibility by 4
- Divisibility by 8
- Divisibility by 3
- Divisibility by 6
- Divisibility by 9
- Divisibility by 5
- Divisibility by 11
Sets
Ratio
Proportion (Including Word Problems)
Unitary Method
Fractions
- Concept of Fraction
- Types of Fractions
- Concept of Proper and Improper Fractions
- Concept of Mixed Fractions
- Like and Unlike Fraction
- Concept of Equivalent Fractions
- Conversion between Improper and Mixed fraction
- Conversion between Unlike and Like Fractions
- Simplest Form of a Fractions
- Comparing Fractions
- Addition of Fraction
- Subtraction of Fraction
- Multiplication of Fraction
- Division of Fractions
- Using Operator 'Of' with Multiplication and Division
- BODMAS Rule
- Problems Based on Fraction
Decimal Fractions
Percent (Percentage)
Idea of Speed, Distance and Time
Fundamental Concepts
Fundamental Operations (Related to Algebraic Expressions)
Substitution (Including Use of Brackets as Grouping Symbols)
Framing Algebraic Expressions (Including Evaluation)
Simple (Linear) Equations (Including Word Problems)
Fundamental Concepts
Angles (With Their Types)
Properties of Angles and Lines (Including Parallel Lines)
Triangles (Including Types, Properties and Constructions)
Quadrilateral
Polygons
The Circle
Symmetry (Including Constructions on Symmetry)
Recognition of Solids
Perimeter and Area of Plane Figures
Data Handling (Including Pictograph and Bar Graph)
Mean and Median
- Introduction
- Reading and Writing Large Numbers Using the Hindu-Arabic System
- Examples
- Real-Life Application
- Tips, Tricks, and Common Mistakes
Introduction
Whenever you see a six-digit cheque amount, read India’s population, or hear about a winning lottery, you’re seeing the Hindu-Arabic (Indian) System in action. It helps us make sense of large numbers in daily life!
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10 Digit: Uses symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
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Base-10 System: Each place’s value increases tenfold as you move left.
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Place Value: The value of each digit depends on its position (ones, tens, hundreds, etc.).
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Zero as Placeholder: Allows for representation of any number, large or small.
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Origin: Developed in India and spread by Arab scholars.

Reading and Writing Large Numbers Using the Hindu-Arabic System
In the Indian System, also called the Hindu-Arabic System, to read and write large quantities with ease, the groups are made with certain periods, as shown below:
| Value | 10,00,00,000 | 1,00,00,000 | 10,00,000 | 1,00,000 | 10,000 | 1,000 | 100 | 10 | 1 |
| Period | Ten crore (TC) | Crore (C) |
Ten Lakhs (T L) |
Lakh (L) |
Ten Thousand (T Th) |
Thousand (Th) |
Hundreds (H) |
Tens (T) |
Ones (O) |
Reading and Writing Large Numbers Using the Hindu-Arabic System:
| Periods → |
Crores | Lakhs | Thousands | Ones | |||||
| ↓ Numbers | (TC) | (C) | (TL) |
L |
(TTh) | (Th) | (H) | (T) | (O) |
| 7456123 | 7 | 4 | 5 | 6 | 1 | 2 | 3 | ||
| 225437 |
|
|
2 | 2 | 5 | 4 | 3 | 7 | |
| 61786425 |
|
6 |
1 | 7 | 8 | 6 | 4 | 2 | 5 |
| 82854137 |
|
8 |
2 | 8 | 5 | 4 | 1 | 3 | 7 |
| 743813256 | 7 | 4 | 3 | 8 | 1 | 3 | 2 | 5 | 6 |
Examples
- 7456123 = 74,56,123
= Seventy-four lakh fifty-six thousand one hundred twenty-three. - 82854137 = 8,28,54,137
= Eight crore twenty-eight lakh fifty-four thousand one hundred thirty-seven. - 61786425 = 6,17,86,425
= Six crore seventeen lakh eighty-six thousand four hundred twenty-five. - 82854137 = 8,28,54, 137
= Eight crore twenty-eight lakh fifty-four thousand one hundred thirty-seven. - 743813256 = 74,38,13,256
= Seventy-four crore thirty-eight lakh thirteen thousand two hundred fifty-six.
Note:
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Don’t use plurals when writing numbers in words (e.g., write five thousand, not five thousands).
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Don’t use “and” between tens and ones in number words (e.g., write five hundred ninety-three, not five hundred and ninety-three).
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Don’t use commas when writing numerals like 2,468. Instead, write Two thousand four hundred sixty-eight.
Real-Life Application
1. A check for ₹23,45,678 is written as
- 23,45,678 (figures)
- Twenty-three lakh forty-five thousand six hundred seventy-eight (in words)
2. Population data: “1,38,00,00,000” is spoken as “one hundred thirty-eight crore.”
Tips, Tricks, and Common Mistakes
- Commas: Always write from the right: first three digits, then every two digits.
- No “and” in words. Don’t use “and” (e.g., NOT “two hundred and fifty”).
- No plurals: Use “lakh”, not “lakhs.”
- Commas only in figures, not in words.
- Zero is never at the start (e.g., “07,21,096” is just “7,21,096”).
